To see the other types of publications on this topic, follow the link: Biogas Technology.
Dissertations / Theses on the topic 'Biogas Technology'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Biogas Technology.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Shah, Bilal. "Distributed biogas production for biogas fuel." Thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-218021.
Full text
2
Henderson, Elizabeth A. (Elizabeth Anne) Carleton University Dissertation International Affairs. "Biogas technology in Tanzania: a feasibility study." Ottawa, 1991.
Find full text
3
Saldarriaga, David. "Small-Scale Biogas Upgrading System Modeling Tool Development." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235924.
Full textAbstract:
The potential of biogas to decarbonize society depends partially on the success of small-scale systems. Two specific locations where biogas units can be implemented are considered in this study: small farms and small isolated populations. The access to energy sources, either traditional or renewable for these is often restricted and typically costly. Clean raw biogas can be the energy source to satisfy power generation, cooking, and heating needs. Upgrading widens the options to transport fuel and energy storage helping positively in the unlinking between production and demand. Water upgrading has three essential and exclusive benefits that make it a highly feasible solution for these isolated locations or small agricultural units. It is in general available in these places; it has a very low environmental impact if leakage or malfunctioning of the system, and has no toxicity per se. To aid the development of the biogas industry focused on small-scale systems a fast, easy to use, low cost, customizable tool is needed to help the design process of the high-pressure water upgrading units. The present study covers the development of such a tool. In the present report, the basis of the model to solve the mass balance of the system and to calculate the dimensions of the scrubber are described. The scrubber model is an implementation of the NTU-HTU model proposed by Billet and Schultes in two major publications (Billet, 1995) and (Billet & Schultes, 1999). The strategies used to solve the set of closed loop equations, and iterations are presented in a block diagram fashion. The tool was developed in visual basic for applications using Excel as the hosting application. The results of the tool are compared against those obtained from the same model ran in Aspen Plus. To perform such a comparison, 540 cases were used. The cases are the result of running three nominal raw biogas flows, using three different packing materials, varying the raw biogas and water flows, varying pressure, temperature, and height of the scrubber, and varying the pressure of the flash tank. Three sensitivity analyses are performed to check the influence of some variables in the model. One is designed to check the influence of the exponent choice for dimensionless numbers in the calculation of the volumetric mass transfer coefficient as an example of the various points where the Billet model is adjusted to follow the behavior of packed columns. Another analysis consists of comparing the results of height using different packing materials to see how the six packing constants affect the results of the calculations. The third analysis is performed to check the influence of the methane absorption model where three different approaches were used. The results show that the tool behaves coherently, and a validation step can be implemented via real experimental tests comparison. The tool has several points where adjustments can be made, like the mentioned exponents for the dimensionless numbers, or the constants used in the interfacial area calculation and the correction of the 𝐶𝑆 and 𝐶𝐹𝑙 packing constants when inversion point has been reached. The implementation of high-pressure water scrubbing together with a flash tank can achieve slip values as low as 0.25% or even lower. The lower the slip, the higher the energy needed to upgrade is. Thus, there is a trade-off between slip and internal energy demand.<br>Potentialen hos biogas för att minska samhällets kolberoende är delvis beroende avframgången för småskaliga system. I denna studie betraktas två specifika platser där biogasenheter kan användas: små lantbruk och små isolerade byar. Tillgången till energikällor, såväl traditionella som förnybara, är ofta begränsad och är vanligtvis dyr för dessa platser. Renad biogas kan bli enenergikällan för att tillgodose kraftproduktion, matlagning och uppvärmning. Biogasuppgradering breddar användningsalternativen till användning som drivmedel och till energilagring, vilket bidrar på ett positivt sätt till koppla isär energiproduktion och energiförbrukning. En vattenskrubber har tre viktiga och unika fördelar som gör den en väldig användbar lösning för dessa isolerade platser eller för små jordbruksenheter. Vanligtvis är vatten tillgängligt på dessa platser, det har en synnerligen låg miljöpåverkan om det blir läckor eller funktionsfel i systemet och det är icke-giftigt. För att stödja utvecklingen av biogasindustrin med inriktning på småskaliga system behövs ett snabbt, lättanvänt, billigt och anpassningsbart verktyg för att genomföra design en högtrycks vattenskrubber. Den här studien omfattar utvecklingen av ett sådant verktyg. I föreliggande rapport beskrivs grunden för modellen för att lösa systemets massbalans och att beräkna och dimensionera skrubbern. Skrubber-modellen innehåller en implementering av NTU-HTU-modellen som Billet och Schultes föreslagit i två stora publikationer (Billet, 1995) och (Billet & Schultes, 1999). De strategier som används för att lösa uppsättningen av slutna loop-ekvationer och iterationer presenteras i ett blockdiagram. Verktyget har utvecklats i VBA (Visual Basic for Applications) och använder Excel som programvarumiljö. Resultaten som erhålls med det utvecklade verktyget jämförs med de som erhålls från samma modell i Aspen Plus. För att utföra en sådan jämförelse användes 540 testfall. Fallen är resultatet av modelleringen av tre nominella biogasflöden, där tre olika typer av fyllmaterial/fyllkroppar används. För varje testfall varieras rå biogas, vattenflöde, tryck, temperatur och höjd av vattenskrubbern, samt trycket i flash-tanken. Tre känslighetsanalyser utförs för att kontrollera påverkan av vissa variabler i modellen. Den första är utförmad för att kontrollera exponeringsvalets inverkan på dimensionslösa tal vid beräkningen av den volymetriska massöverföringskoefficienten, som ett exempel av flera punkter där Billets modell är justerad för att följa vattenskrubbers beteendet. Den andra analysen består av att jämfora skrubberns beräknade höjd när olika fyllmaterial används för att evaluera hur påverkar de sex fyllmaterial konstanterna resultaten av beräkningar. Och den tredje analysen utförs för att kontrollera påverkan av metans absorptionsmodell när tre olika metoder användes. Resultaten visar att verktyget uppträds på ett koherent sätt och ett valideringssteg kan baserat på detta genomföras med verkliga experimentella jämförelser. Verktyget har flera delar där justeringar kan göras, som t.ex. exponenterna för dimensionslösa tal och konstanterna som används i interfaceberäkningarna, samt korrigeringen av 𝐶𝑆 och 𝐶𝐹𝑙 konstanter när punkten av inversion har uppnåtts. Implementeringen av högtrycks vattenskrubbers tillsammans med en flash-tank kan medföra en slipp (förklaras senare i rapporten) så låg som 0,25% eller ännu lägre. Ju lägre slipp är desto högre är energin som behövs för att uppgradera biogasen. Det finns således en avvägning mellan slipp och intern energiförbrukning
4
Larsson, Anneli. "Profile and perceptions of biogas as automobile fuel : A study of Svensk Biogas." Thesis, Linköping University, The Tema Institute, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12507.
Full textAbstract:
<p>From an environmental- and health perspective, biogas and other biomass-based fuels have several advantages; nevertheless the majority of motorists fill their cars with petroleum-based fuels. This thesis is designed to explore the profile of biogas in relation to its perceptions. It is a study concerning the communication between the biogas producing company Svensk Biogas and their biogas users and non biogas users. To obtain a thorough understanding of the profile and perceptions of biogas a qualitative approach was considered appropriate. Biogas users and non-users were interviewed at gasoline stations, while Svensk Biogas was interviewed as a group.</p><p>The three interview segments were analyzed and compared in order to identify patterns, similarities and differences. Based on research data the thesis concludes that the profiling arguments of biogas correlates to that biogas is the most environmentally friendly fuel, the least expensive fuel, and locally produced. Furthermore, the company profile of Svensk Biogas is equal to sustainable alternative, locally produced, trustworthy, environmentally friendly and climate smart [klimatsmart]. Given the arguments of the company profile, environmental values seem to be the core communicating value. Profiling Svensk Biogas happens through events and by using communication material such as company logotype.</p><p>Motorists have an overall positive perception of biogas. Biogas users states environmental benefits as the key argument behind their commitment. Non-users are positive toward biogas although expressing a lack of knowledge confusing biogas with ethanol and bio-fuels in general. According to motorists the negative perceptions, in addition to the prerequisites of biogas, are connected to insufficient infrastructure of biogas filling stations, a short range of the biogas tank, a high investment cost of a biogas car, a biogas price increase, scarcity of cars, and information (lack of information and misleading information).</p><p>The overall perception of Svensk Biogas among biogas users is positive. Biogas users express a negative perception concerning the Svensk Biogas filling stations and also wish for a lower biogas price. Non-users express modest perceptions of the company. This research also concludes that perceptions of the biogas producer are correlated to the perceptions of biogas. Furthermore, biogas producer, users and non-users wish to be directed by political decisions, guiding them toward environmentally friendly fuel alternatives.</p>
5
Johansson, Tobias, and Theo Målsten. "Wasted Biogas : Economic analysis of biogas recovery adjoined to existing incineration facility in Sweden." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279672.
Full textAbstract:
Biogas is of growing interest in Sweden, and a public inquiry suggested the government to set a goal of producing 10 TWh biogas in 2030 although only 2 TWh biogas was produced in Sweden in 2018 (Regeringskansliet, 2019) (Klackenberg, 2019). To achieve this optimistic goal and to meet the increased demand of biogas, new biogas production facilities needs to be built. The purpose of this report is to investigate the economic feasibility for the development of a biogas recovery process adjoined to an incineration facility in Sweden. The report first gives an overview of the largest incineration facilities in Sweden. The largest quantity of food waste was estimated in Gothenburg to be 56´744 WRQ SeU \eaU. For the economic feasibility, a conceptual facility was constructed with 169´000 ton residual waste per year of which 45´000 ton was food waste. A biogas process model was built in Excel where the biogas potential was calculated using characteristics for food waste. The annual production of liquid biogas was estimated to 43´970 MWK. The economic evaluation was based on the conceptual facility. In the baseline scenario the incomes for the process was the value of liquid biogas, 25,6 MSEK per year, a Gate-fee synergy of 5 MSEK per year and a Tax deduction synergy of 1 MSEK per year. The investment cost was estimated to 211,6 MSEK and the Operation & Maintenance cost was estimated to 6,3 MSEK per year. This resulted in an NPV of 69,5 MSEK and an IRR of 10,3% for the project, indicating a profitable investment. Three different scenarios were considered, apart from the baseline scenario, where the first excluded all synergies with the incineration facility, which generated an NPV of 2,3 MSEK. The second scenario only considered the minimal gate-fee synergy which gave an NPV of 37,8 MSEK. Finally, the third scenario where all synergies were included, and an additional investment grant was introduced gave the project an NPV of 111,8 MSEK. A sensitivity analysis was also conducted which showed that the input of food waste treated, weighted average cost of capital and potential grants had the biggest impact on the financial results. None of the results from the sensitivity analysis showed a negative NPV.<br>Intresset för biogas växer i Sverige och i en statlig utredning föreslogs regeringen att sätta upp ett mål att producera 10 TWh biogas 2030 (Regeringskansliet, 2019). Detta kan jämföras med 2018 då endast 2 TWh producerades (Klackenberg, 2019). För att uppnå detta optimistiska mål och för att möta den ökade efterfrågan på biogas behöver nya produktionsanläggningar byggas. Syftet med denna rapport är att undersöka de ekonomiska möjligheterna för utvecklingen av en biogasanläggning angränsad till en förbränningsanläggning i Sverige. Rapporten ger först en översikt över de största förbränningsanläggningarna som behandlar hushållsavfall i Sverige. Det uppskattades att den största mängden matavfall som går till förbränning i Sverige är i Göteborg där 56´744 ton matavfall förbränns per år. För att bestämma de ekonomiska förutsättningarna konstruerades en konceptuell anläggning som behandlar 169´000 ton restavfall per år varav 45 000 ton består av matavfall. En biogasprocess modellerades i Excel där den potentiella biogasen beräknades baserat på matavfallets karaktäristik. Slutligen uppskattades den årliga produktionen av flytande biogas till 43´970 MWh. Den ekonomiska utvärderingen baserades på den konceptuella anläggningen. I grund-scenariot bestod inkomsterna för av den flytande biogasen som motsvarade 25,6 MSEK per år, en ´gatefee´-synergi på 5 MSEK per år och en ´skatteavdrags´-synergi motsvarande 1 MSEK per år. Investeringskostnaden uppskattades till 211,6 MSEK och Operation & Maintenancekostnaderna uppskattades till 6,3 MSEK. Detta gav projektet ett nettonuvärde på 69,5 MSEK och en internränta på 10,3% vilket indikerar en lönsam investering. Vidare undersöktes även tre olika scenarier, utöver grund-scenariot, där det första utesluter alla synergier vilket gav ett nettonuvärde på 2,3 MSEK. Det andra scenariot beaktade endast den minimala ´gate-fee´-synergin vilket gav ett nettonuvärde på 37,8 MSEK. Det tredje scenariot inkluderade alla synergier samt ett investeringsbidrag vilket resulterade i ett nettonuvärde på 111,8 MSEK. En känslighetsanalys genomfördes också som visade att tillförseln av behandlat matavfall, kapitalkostnaden och potentiella investeringsbidrag hade den största påverkan på de finansiella resultaten. Inget av resultaten från känslighetsanalysen visade ett negativt nettonuvärde.
6
Jansson, Joachim. "Anaerobic digestion technology for Swedish conditions and experimental verification of increased biogas production from polyurethane and biomass retention." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-128494.
Full textAbstract:
Anaerobic digestion of farm waste has the potential to revolutionize the agricultural sector. There are four principal objectives of this report. Summarize anaerobic technology and biological function and how they affect the potential of farm scale anaerobic digest in a literary study. Economically evaluate farm scale scenarios where biogas is considered for upgrading, heating and electricity with an internal rate of return method. Simulate farm scale scenarios in the computer software Aspen Plus. In these scenarios biogas is utilised for upgrading, heating, electricity and compared to active anaerobic digesters. Investigate how polyurethane and retention of biomass effects an anaerobic digester through design of experiments. The economic evaluation was done by using the internal rate of return. The results indicate that all scenarios are warranted in different situations but that in the given scenario a CHP unit is the most profitable. Aspen simulations show great promise as a tool for evaluation of different digester systems. It could be used both for economical evaluations and in planning stages. The effects of polyurethane and retention of biomass was shown to effect the methane concentration in the test reactors with up to 15 percentage points and the biogas production with 32 percent. These two models were developed in Modde 10. Thru the literary study the importance for anaerobic digestion technologies to be adapted to conditions were they are to be deployed for them to be profitable were evident. The immense benefits of biogas production on the environment indicates the biogas production will play a part in the conversion to a sustainable energy system.
7
Awosolu, Mary. "Anaerobic digestion of ethanol distillery waste-stillage for biogas production." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19072.
Full textAbstract:
Dependence on oil imported from foreign countries affect the National Energy securitiesand Energy security of global economies has become one of the most challenging problemthat needs to be resolved as the fossil sources are fast diminishing and irreplaceable. Thealarming energy demand and consumption rate of the present global status is currentlyexponentially exceeding the rate of local supply sources, becoming an issue of concern. Alook beyond the fossils is crucial for long tern economic growth and energy security asthere are numerous uncertainties about the fossil supplies coupled with the greaterenvironmental risks encountered during exploitation. Thus the new concept for treatingethanol distillery waste anaerobically to produce Biogas- a clean renewable alternativeenergy with many applications projects sustainable and more realistic option.The research project focuses on Comparison of the Potentials and Efficacy of AnaerobicDigestion of Stillage (Wheat Stillage and Lignocellulose Stillage) from Ethanol Distilleryplants for Biogas Production. It also investigates better alternative temperature dependentStillage Anaerobic Digestion that will enhance a higher Biogas yield.Anaerobic digestions were performed in triplicate batch systems, during both mesophilic(35 °C) and thermophilic (55 °C) conditions at a period of 50-days. The reactors contained2.73g of Wheat Stillage and 5.2g of Lignocellulose Stillage samples, respectively,corresponding to 2% VS in each reactor. The inoculum was taken from either a mesophilicBiogas Plant (Gässlosa., Borås), or from a thermophilic Biogas Plant (Sobacken, Borås). AGas Chromatographic method (GC) was employed for determination of the obtained biogascomposition.The theoretical CH4 Potential for Wheat Stillage and Lignocellulose Stillage is 0.473m3CH4/kg VS and 0.407 m3CH4/kg VS, respectively. The results obtained from this studyindicated, however, that the Wheat Stillage performed better under thermophilic conditionswith a peak of 575ml CH4 / 0.5g VS; while the Lignocellulosic Stillage gave the bestperformance under mesophilic conditions leading to a methane production of 436ml CH4/0.5g VS after 4 weeks of digestion period.<br>Uppsatsnivå: D
8
Mejia, Dugand Santiago. "Evaluation of the Availability of Raw Materials for Biogas Production in Medellín, Colombia." Thesis, Linköpings universitet, Industriell miljöteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-65634.
Full textAbstract:
This master thesis investigated the availability of raw materials for biogas production in the city of Medellín, Colombia. By first studying the development of biogas and its use as a vehicle fuel in the city of Linköping, Sweden, a comparison was made in order to focus on high-yield substrates. The objective was to calculate potential production given the amounts and types of substrates found locally and comparing it with the estimated demand of a local bus fleet that is planned to run on natural gas. The assessment of the raw materials was made in situ. The planned sources were visited in order to get information that would be later on analyzed for estimating its production potential. These sources were originally a municipal wastewater treatment plant, two slaughterhouses and two biodiesel plants. The wastewater treatment plant is already producing biogas, resulting from the treatment of sludge in anaerobic digesters. Nevertheless, calculations showed that current production is around 54% that of theoretical potential. Regarding the slaughterhouse, several important flows were detected, although some of them would not be currently available for biogas production, as they already have a defined use. The case for biodiesel production in the city was not very successful, as the two plants that were planned to be analyzed, have not started operations yet. However, some assumptions were made and some figures were calculated for further conclusions and analyses. During the visit, some other interesting sources were detected and were included in this report, such as another wastewater treatment plant, two fruits and vegetables markets, two landfills and biodiesel production in other areas. Several interesting points were discussed and analyzed through a comparison of the two cities. Drivers, barriers, actors, raw materials and production capacity were summarized and compared, resulting on reflections and conclusions. The results were also interesting, showing that the biogas potential at the two wastewater treatment plants would be enough to fuel the system and that if the other sources were to be used, excess biogas would be available for other uses, e.g. private cars or injection into the natural gas grid.<br>Det här examensarbetet undersöker tillgången på råvaror för biogasproduktion i Medellín, Colombia. Genom att först studera utvecklingen av biogas och dess användning som bilbränsle i Linköping, Sverige, gjordes en jämförelse för att fokusera på hög substrat avkastning. Syftet var att beräkna möjlig produktion utifrån de mängder och typer av substrat som går att finna lokalt, och därefter jämföra detta med ett bussbolags uppskattade efterfrågan av naturgas. Värdering av råvaror gjordes in situ. De planerade källorna besöktes för att få information som senare kan analyseras för att värdera dess produktionsmöjlighet. Källorna var ursprungligen ett avloppsreningsverk, två slakterier och två biodiesel produktionsverk. Avloppsreningsverket producerar redan biogas, med vattenrengöring på anaeroba slam digestorer. Trots detta visade beräkningar att nuvarande produktion utgjorde ungefär 54% av den teoretiska möjligheten. I fråga om slakteriet, upptäcktes flera viktiga flöden, även om några inte skulle vara tillgängliga för biogasproduktion, då de redan användes för något annat. Studien om biodiesel produktionen i staden var inte lyckad, eftersom de två produktionsanläggningarna som skulle analyseras, ännu inte startat sina verksamheter. Dock var några antaganden gjorda och några siffror beräknade för ytterligare slutsatser och analyser. Under besöken upptäcktes några andra intressanta källor, så som andra avloppsreningsverket, två frukt- och grönsaksmarknader, två soptippar samt biodiesel produktion i andra områden. Flera intressanta punkter har diskuterats och analyserats genom jämförelsen mellan de två städerna. Förare, hinder, aktörer, råvaror och produktionskapacitet sammanfattades och jämfördes, vilket resulterat i reflektioner och slutsatser. Resultatet var också intressant, då det visar att potentialen för biometan på de två reningsverken skulle vara tillräcklig för att driva systemet, samt om andra källor användes skulle det finnas överskott på biometan för annan användning, t.ex. personbilar eller injektioner i naturgasnätet.
9
Lilja, Nattika. "Biogas av tång och alger : Möjligheter och hinder." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-36846.
Full textAbstract:
I detta examensarbete studerades metanpotentialen för brunalger och rödalger som hämtades vid två olika tillfällen. Förutsättningarna för att tång och alger ska kunna användas som substrat för biogasproduktion samt vilken miljönytta som kan uppnås undersöktes också. Satsvisa försök har gjorts i laboratoriemiljö genom att ta reda på metanpotentialen för de olika substraten. Biogasproduktion skedde i en syrefri rötningsprocess som innebar ett komplext förlopp där olika mikroorganismer sönderdelade substratet i flera steg för att slutligen bilda biogas samt en rötrest. Ympen som användes i försöket kom från en biogasanläggning och bestod av en blandning av naturgödsel och organiska restprodukter från slakterier och annan industri. Substratblandningar mellan tång och rötrest undersöktes genom satsvis teströtning i 15 flaskor under mesofila förhållanden, 37 °C. Gasmätningar utfördes kontinuerligt under försökets gång. Metanhalter analyserades med en gaskromatograf. Testerna avslutades efter 17 dagar eftersom produktionen för samtliga flaskor då hade upphört. Resultatet visar att samrötning av rödalger som hämtades i oktober med ymp genererade en högre metanpotential än andra substrat. Den högsta metangaspotentialen var 159 l/kg VS. Rödalger som inhämtades i januari genererade lägst metangaspotentialen, cirka 60 l/kg VS. Att samla upp tång och alger från stränder innebär många fördelar. Exempelvis att ta bort lukt, att öka rekreationsvärdet, att förbättra vattenkvaliteten, att minska övergödningen samt att stränderna blir mer badvänliga. Genom att framställa biogas från tång ökar dessutom produktionen av förnybar energi. Energin från biogas uppvisar mycket hög klimatprestanda och bidrar till en minskning av utsläpp av växthusgas.
10
Vu, Thi Nguyet, Van Tua Tran, Dinh Kim Dang, Thi Kim Anh Bui, and Hai Yen Vu. "Application of ecological technology for removal of COD, nitrogen and phosphorus from piggery wastewater after biogas production technology." Technische Universität Dresden, 2016. https://tud.qucosa.de/id/qucosa%3A32627.
Full textAbstract:
Despite a positive contribution to economic – social development, the growth of piggeries has caused heavily environmental pollution. Currently, treated wastewater of pig farms unfortunately does not meet the national discharge standards yet. This paper presents some research results on the removing COD, nitrogen and phosphorus in piggery wastewater after anaerobic (biogas) process at pilot scale by the combined system using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes. The experimental results showed that the wastewater loading rate of 47.35 l/m2.day with initial concentrations of 203.24 mg COD/l, 111.94 mgTN/l and 13.61 mgTP/l gave removal efficiency of 71.66 %, 79.26 % and 69.65 %, respectively. Thus, the removed quantity of total nitrogen (TN) and total phosphorus (TP) was of 4201.35 mg TN/m2.day và 448.76mg TP/m2.day. The obtained results indicated that the flow wetland system, using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes has a rather high COD, TN and TP removal efficiency with simple operation so that it could be feasible if applied for treating pig wastewater. However, the system should be functioned longer for taking data and for evaluating its stability.<br>Mặc dù có những đóng góp tích cực cho sự phát triển kinh tế - xã hội, việc phát triển chăn nuôi lợn đã gây ô nhiễm môi trường nghiêm trọng. Hiện nay, nước thải chăn nuôi lợn từ các cơ sở chăn nuôi sau xử lý vẫn chưa đáp ứng được các tiêu chuẩn thải của quốc gia và tiêu chuẩn ngành. Bài báo này trình bày kết quả nghiên cứu về khả năng loại bỏ COD, nitơ (N) và phôtpho (P) trong nước thải
chăn nuôi lợn đã qua xử lý bằng hầm biogas của hệ thống phối hợp cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây ở qui mô pilot. Kết quả thực nghiệm ở tải lượng 47,35 l/m2.ngày, với COD, tổng nitơ (TN) và tổng phôtpho (TP) đầu vào trung bình là 203,24 mg/l, 111,94 mg/l và 13,61 mg/l, tương ứng, thì hiệu suất xử lý lần lượt là 71,66 %; 79,26 % và 69,65 %. Như vậy lượng TN và TP loại bỏ là 4201,35 mgN/m2.ngày và 448,76 mgP/m2.ngày. Kết quả nhận được cho thấy hệ thống sử dụng cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây có hiệu quả loại bỏ COD, TN và TP khá cao trong khi vận hành đơn giản nên có triển vọng áp dụng trong điều kiện thực tế để xử lý nước thải chăn nuôi lợn. Tuy nhiên để đánh giá tính ổn định, hệ thống cần được hoạt động với thời gian lâu dài hơn.
11
Thom, Cecile. "The application of biogas technology in South Africa for small-scale energy production." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/9631.
Full textAbstract:
Bibliography: leaves [141]-145.<br>This study has aimed to contribute to the development of low-cost or "simple" biogas technology, i.e. the design, construction, operation and utilisation of relatively simple biogas systems in South Africa, and to explore the utilisation of the technology by lower-income groups in the rural areas of the country, particularly in the former homelands. Specific objectives included the development of biogas plants suitable for application in South Africa, and the assessment of the acceptability of the technology among potential users. Five biogas plants were constructed during the study, which provided the opportunity to test various designs and obtain response from some of the potential users of the technology.
12
Roubík, Hynek. "Small-scale biogas technology in Southeast Asian countries: current state, bottlenecks and perspectives." Doctoral thesis, Česká zemědělská univerzita v Praze, 2015. http://www.nusl.cz/ntk/nusl-260289.
Full textAbstract:
Biogas produced via the anaerobic digestion (AD) of organic waste materials is considered as an important technology in improving the environment because it solves waste management problems and simultaneously produces biogas as a main product and digestate as a by-product, which can also be used as a fertilizer.
Within the rising expectations for the substitution of fossil energy with renewable energy as one of the solutions to cope with climate change, the environmental aspects of small-scale biogas plants, as widely used method for energy creation, should be evaluated in a holistic and systematic way. The use of small-scale biogas plants is mostly common for energy creation from waste in Southeast Asia.
This source of energy is mainly lauded for its low costs, clean production and high fertilization effects of digested matter for crops. There are number of advantages of small-scale biogas production on farms, including also savings on firewood or fossil fuels and reduction in odour and greenhouse gas emissions from using other fuels. However, biogas plants are often poorly managed and there is lack of proper distribution systems for biogas. That results in methane being release inadvertently through leaks in digesters and tubing, and intentionally when production exceeds demand. As methane has a global warming potential 25 times higher than that of carbon dioxide, environmental advantages of small-scale biogas plants might be compromised.
This dissertation intends to provide in-depth understanding about the issue with taking into accounts possible risks. Investigating of such a topic is within continuing concern about small-scale biogas technology in rural areas of developing countries. For this reason technical, social, economic and environmental assessment of small-scale biogas technology will be done. Methods of data collection will consist of questionnaire survey and focus group discussions among randomly selected owners of biogas plants, semi-structured personal interviews with local authorities and facilitators and observation. Furthermore, prediction of future development of this technology will be created.
13
Lamond, Alexander Robert. "Techno-economic and carbon emissions analysis of biogas utilisation systems in the UK." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50376/.
Full textAbstract:
Biogas is a renewable and carbon neutral fuel, that can help the UK meet its increasing energy demand, while simultaneously reducing the net greenhouse gas emissions. All the biogas utilisation routes modelled, return positive avoided greenhouse gas (GHG) emissions. Biogas to combined heat and power (CHP) returns higher avoided emissions than biogas upgrading to biomethane and injection into the gas grid across the entire heat utilisation range (0% to 100%). The current renewable energy incentives, offered by the UK government, allow utilising biogas via either CHP, or biomethane production to return positive net present values (NPV). A theoretical membrane with improved separation properties (termed "future" membrane) allows reduction in energy consumption and increase in NPV. The future membrane returns positive net present values without the aide of subsidies, however, subsidies are required in order to compete with biogas to CHP. When 2014 subsidies were applied (7.7 pence/kWh of biomethane), the future membrane returned a higher NPV (£28.3million) than biogas to CHP (£27.5million). The proposed development fuel maximum buy-out for biogas derived transport fuels would make the minimum selling point (MSP) of upgraded biogas transport fuel lower than diesel by 2-10 pence/kWh. Enriching biogas with natural gas is a lower cost method of achieving a gas mix that complies with internal combustion engine specifications than upgrading biogas with either current membranes, or future membranes. However, the renewable fraction of the final transport fuel would only contain a maximum renewable energy fraction of 30%, if enriching biogas with natural gas. The largest overall contributor to producing biogas derived transport fuel is the cost of producing biogas.
14
Pandiyan, Ishwarya, and Sailaja Gudipudi. "Effect of fruit flavor compounds on biogas production." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17515.
Full textAbstract:
The purpose of the experiment was to investigate the effect of fruit flavor compounds on biogas production from fruit wastes. The flavor compounds from different fruits were selected and synthetic medium was used throughout the experiment. The experiment was carried out both in batch and continuous process using thermophilic inoculums obtained from Söbacken waste management plant. The inhibitors were added at three different concentrations 0.05g/L, 0.5g/L and 5g/L respectively and were carried out in triplicates for batch cultivation.The result from batch cultivation showed that hexanal, (E)-2-hexanal, myrcene and octanol showed inhibitory activity. Hexanal, (E)-2-hexanal, myrcene, and octanol decreased biogas production by factor of 316.8%, 434.22%, 329.68% and 433.61% at concentration of 5g/L. Continuous experiment was carried out on Automatic Methane Potential Test System AMPTS II. Eight reactors, each with inhibitor compounds were used with a retention time of 30 days and an organic loading rate of 3g VS/day. The inhibitor concentration was increased from 0.5g/L to 5g/L and for some compounds up to 10g/L. During cultivation, several factors were measured periodically such as pH, total biogas production, biogas composition, FOS/TAC and VFA.The inhibitory effect was clearly shown at concentration higher than 0.5g/L. Addition of 5g/L hexanal, nonanal, (E)-2-hexanal, α-pinene , car-3-ene, myrcene and octanol resulted in reduction of biogas production by 81.2%, 4.67%, 50.74%, 7.06%, 24.01%, 31.84% and 52.85% respectively. When compared to batch process, continuous process required higher concentration of flavor compounds to reduce biogas production. This might be due to adaptation of cells towards toxic compounds during continuous process.<br>Program: Master of Science with a major in Resource Recovery-Industrial Biotechnology
15
Rajendran, Karthik, and Gopinath Balasubramanian. "High rate biogas production from waste textiles." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20787.
Full textAbstract:
Textile is a global product used by all people in the world. These textiles after the use are thrown into the trash for incineration or land filling. However an efficient way that can be used to produce more energy, in an environmentally friendly process is anaerobic digestion. Waste textiles which contain cellulosic fibers (e.g. Cotton and viscose) can be converted to biogas. In this study, the performance of a two-stage anaerobic digestion process for biogas production from four different materials, including untreated jeans, treated jeans, cotton, and starch was studied. Starch was used as an easy-to-digest material to compare its digestion with that of cellulosic materials.The two-stage processes were composed of a CSTR (for hydrolysis) and a UASB (for methanogenisis) which were investigated in two different configurations, namely (closed and open systems). In the closed system, the outlet of UASB was completely returned back to the CSTR, while in the open system the UASB outlet was sent to sewage. In a stepwise progress, the OLR was aimed to increase from 2 to 20 g Vs per L per day along with reduction in hydraulic retention time from 10 days to 1 day.The results showed that the closed system was more stable when compared to the open system. The pre-treatment of jeans by NMMO helped to produce methane as that of cotton. The hydraulic retention time was decreased to less than 9 days for treated jeans and less than 5 days for starch. The overall methane yield at OLR of 4 gVS per L per day for starch and treated jeans was 98.5% and 97.4% in the closed system, whereas in the open system the yield was 77.0% and 35.5%, respectively.Another experiment was conducted to compare the performance of two-stage process with that of a single stage process of anaerobic digestion of textiles containing polyester and cotton or viscose. Viscose textiles produced more gas compared to the cotton textile; it may be due to the higher crystalline of cotton which makes it hard to be degraded by the microorganisms. Furthermore, two-stage process could able to produce more methane than the single stage process.The parameters like total solids, volatile solids, pH, gas production, gas composition, concentration of nutrients, and COD were also analyzed for both of the experiments.
16
Yngvesson, Johan. "Experimental Design and Optimization of Hydrolysis of Paper for Biogas Production." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20791.
Full textAbstract:
The waste production in Sweden and Europe is increasing each year. Swedish households throw away 2.7 million tonnes material annually and because of though waste legislations, most of this is recycled as material or energy. The Swedish goal to increase the amount of biologically treated food waste and also to increase the biogas production requires not only investments but research in this area. Increased biogas yield from anaerobically treated waste materials will be beneficial to reach the goals. About 45 % of the biological waste consists of lignocellulosic material. Lignocellulose is also the most abundant renewable material in the world which makes it very interesting for biogas production. Sweden is also a country were over 10 % of its total export value is generated from the forest industry. An industry which produces large amounts of waste streams. In this thesis work the author investigates how hydrolysis can increase the digestibility of industrial waste paper. The scope was to find an efficient pretreatment method of paper and determine which affecting factors levels are the most successful ones. A literature study was followed by a series of experiments in order to find the optimal parameters for pretreatment of an industrial waste paper with the goal to increase its digestibility for anaerobic biogas production. From the study three pretreatment methods for hydrolysis of paper were chosen and an experimental design was conducted. The methods were hot water, alkali and wet oxidation. The result of the treatment was evaluated by measuring the soluble chemical oxygen demand (sCOD) in the supernatant of each treated samples and then analyse the results using a statistical software program. The highest levels of dissolved organic materials was found in samples treated at 250 °C for 30 minutes and with 2 % additive concentration of NaOH. The result was 42 g/l from a suspension of dry milled paper tubes of 50 g/l. By using the results in an analysis of variance it was possible to determine that sodium hydroxide was the most significant factor for hydrolysation of paper, followed by temperature and then addition of hydrogen peroxide. The results also revealed that there are no interaction effects between the examined factors in any of the tested methods.
17
Narang, Kritika. "Tailoring of adsorptive properties of zeolites for biogas upgrading." Licentiate thesis, Luleå tekniska universitet, Materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73868.
Full textAbstract:
Biogas is a promising alternative fuel with low CO2 emissions and high market potential due to the abundance of organic biomass. Despite being a renewable form of energy, biogas consists of 40-45% CO2, which lowers its calorific value [1]. Various porous materials have been tailored to adsorb CO2 gas from the biogas stream to obtain 95-97% biomethane. Zeolites are one of the promising porous materials that can contribute remarkably in the upgrading process by selectively adsorbing the CO2 gas from biogas [2]. The aim of this thesis is to develop hierarchical structures by novel approaches to enhance their CO2 adsorptive properties. The first part of the study addresses the tailoring of zeolites NaX and CaA binderless beads using the ion-exchange process to acquire high CO2 adsorption capacities of 5.1 mmol/g and 4.3 mmol/g at 298 K with the high mechanical strength of 2 MPa and 1.3 MPa respectively. The ion-exchange process was optimized for NaX and CaA zeolite to obtain high CO2-over-CH4 selectivity of 525 and 1775 respectively. The breakthrough experiments show that the partially ion-exchanged zeolite NaX has high mass transfer kinetics with a CO2 uptake rate of 2.8 mg of CO2/g/s as compared to the zeolite CaA binderless beads. The second part dealt with the structuring of zeolites using freeze granulation and electrospinning techniques. The freeze granulation process was optimized to form granules of 2-3 mm in diameter from NaX and CaA zeolite powder. The CO2-over-CH4 selectivities were investigated using Henry’s law and it shows that the NaX granules offer high selectivity of 214 than the CaA granule, 172 at 273 K and 100 kPa. No physical damage was observed when the granules were subjected to five cyclic breakthrough adsorption-desorption experiments at 4 bar. In addition, NaX granules offer a high uptake rate of 3.6 mg of CO2/g/s with a mass transfer coefficient of 1.3 m/s as compared to the CaA granules. To move further in structuring techniques, electrospinning was used to fabricate hierarchical porous structures. ZSM-5 nanofibers composites were developed from the ZSM-5 nanopowder and polyvinylpyrrolidone (PVP) polymer. Two-step post thermal treatments were carried out: Pre-oxidation and carbonization on ZSM-5 nanofibers composites to form mechanically strong composite structures. The post-carbonized structures showed a 30.4% increase in specific BET surface area than the ZSM-5 nanopowder with the CO2 uptake of 2.15 mmol/g. To investigate the CO2 separation properties, secondary pellet structures were developed with a tensile strength up to 6.46 MPa. The CO2 uptake rate for pellets was 2.3 mg of CO2/g/s without any performance decay after the first cycle with the simulated mass transfer coefficient of 1.24 m/s. [1] J Wang. Decentralized biogas technology of anaerobic digestion and farm ecosystem: Opportunities and challenges, Front.Energy Res. 2 (2014). [2] RV Siriwardane, M- Shen, EP Fisher, J Losch. Adsorption of CO 2 on zeolites at moderate temperatures, Energy Fuels. 19 (2005) 1153-1159.
18
Wei, Xiaoping. "Assessing the Social Impacts of a Sustainable Technology: The Biogas Program in Rural China." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420731804.
Full text
19
Lukong, Pius Nyuykonge. "A value-added mechanism in optimising biogas production with biochar pyrolysis products." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-36585.
Full textAbstract:
While biogas stands a greater chance in substituting fossils fuels and contributing to the reduction of GHG emissions, its major setbacks still rely on its effective price compared to that of fossil fuels in the world market. Its production efficiency and related operational cost can give it a true competitive meaning to fossil fuels regarding upgrading and logistic cost of handling digestate. This study was aimed at investigating the possibility and the extent to which biochar could be used in optimising biogas production with biochar as a pyrolysis product. Two separate experiments were conducted during which the additions of varied quantities of low temperature (500°C), wood-based-biochar were added to anaerobic digestion of lignocellulose biomass (Phragmites australis) at the same inoculum to substrate ratio. It was observed that biochar additions at ratios of 1:1, 1:2, and 1:3 [inoculum: biochar] l/g had a positive effect in stimulating microbial activity which increased biogas production and methane concentrations. The additions were found to improve specific methane yields compared to normal feedstock mixed with inoculum. Furthermore, the biochar addition with the highest effectiveness was 0.5g (1:1) while the dose of 2g and 4g generally limited production of biogas with 4g resulting in a higher inhibition compared to 2g additions of biochar. It was concluded that biochar could play an effective role as a microbial growth stimulating agent (MGSA) in anaerobic digestion. It was also proposed that reusing biodigestate in biochar-based pyrolytic systems to enhance post biochar products could offer solutions to logistic and storage costs of biodigestate to add value in commercialisation of digestate.
20
Emilsson, Arvid, and Andreas Buhrgard. "Towards a prototype of a modular biogas system." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259579.
Full textAbstract:
As of today, large unused potential for biogas production exist within the Swedish agriculturesector. The biogas production within this sector is, however, associated with several problems such as poor energy efficiency and non-profitable systems. This is to some degree due to lack of standardized technical solutions. International Micro BioGas AB (IMB AB) has been aided by KTH since 2014. This project investigates several innovations from IMB AB in regards to biogas production: - A mixing device- A building capturing waste heat from the digesters (building concept)- Insulation of the digester (cover concept)- Small-scale and modular package systems The innovations listed above are evaluated from energy, economic and environmental perspectives by doing a case study on the dairy farm Ogestad close to Gamleby, Sweden. Two cases are considered. In Case 1, the raw biogas is burned in a combined heat and power-unit (CHP) in order to produce electricity. In Case 2, raw biogas is upgraded in a small-scale upgrading unit to vehicle gas standards which is sold to the market. The results show that the mixing device is promising in terms of energy use. It is therefore recommended to move on with testing of the equipment. The cover concept and the building concept show similar performance from energy and environmental standpoints. The building concept is concluded not to be economically viable. The cost reduction by applying a modular concept where one product can be used on different sized farms is significant. However, the needed investment from the company is large. The goal of achieving a modular system is therefore concluded desirable. The subsidy from the Swedish board of agriculture covering 40 % of the investment cost, has a major impact on the profitability of the systems. Without this subsidy, the systems are not viable in terms of economy. In Sweden, the small-scale vehicle gasproduction (Case 2) was concluded the most profitable as well as the best-performing from energy and environmental standpoints.<br>Inom den svenska jordbrukssektorn finns stor potential för utvidgning av biogasproduktionen. Det finns dock många problem med småskalig biogasproduktion, exempelvis olönsamma och energimässigt ineffektiva system. International Micro BioGas AB (IMB AB) har identifierat att detta till viss del kan bero på bristfälliga tekniska lösningar. Detta då det inte finns någon standardisering av teknik på området. IMB AB har, i samarbete med KTH, sedan 2014 arbetat med olika aspekter av småskalig biogasproduktion. Detta arbete undersöker ett antal innovationer och koncept från IMB AB rörande biogassystem: - En ny metod för omrörning- En byggnad som återvinner värmen från rötkamrarna (byggnadskonceptet)- Ett nytt sätt att isolera rötkamrarna (huvkonceptet)- Småskaliga och modulära paketlösningar Innovationerna och koncepten ovan utvärderas från ett energitekniskt, ekonomiskt och miljömässigt perspektiv genom en fallstudie på mjölkgården Ogestad nära Gamleby i Sverige. Två användningsområden för biogasen analyseras. I Fall 1 (Case 1) bränns rågasen i en kraftvärmeanläggning för att producera elektricitet och värme. I Fall 2 (Case 2) uppgraderas rågasen till fordonsgaskvalitet som sedan säljs till marknaden. Resultaten visar att den nya omrörningsmetoden är lovande ur ett energiperspektiv och enrekommendation är att gå vidare med tekniken och göra experimentella studier. Byggnadskonceptet och huvkonceptet visade likvärdiga resultat ur energitekniskt och miljömässigt perspektiv. Byggnadskonceptet konstaterades vara ineffektivt ur ett ekonomiskt perspektiv. Kostnadsreduceringen som uppnås genom att systemet är modulärt och därmed kan produceras i stor skala till olika gårdsstorlekar, är signifikant. Det krävs dock en stor investering från företagets sida. För samtliga fall är systemens lönsamhet starkt beroende av Jordbruksverkets subvention på 40 % av investeringskostnaden och utan den ökar företagetsinvesteringsbehov drastiskt. Med svenska förutsättningar är småskalig produktion av fordonsgas det mest lönsamma samt mest fördelaktiga ur ett miljö- och energiperspektiv.
21
Djurberg, Robert, and Albin Markskog. "Sönderdelning av biomassa för småskalig biogasproduktion." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-228873.
Full textAbstract:
Med de växande hoten från klimatförändringar är det av största vikt att vi minskar vårt beroende av fossila bränslen och börjar använda oss utav mer förnyelsebara energikällor. En utav dessa förnyelsebara energikällor som för oss närmare ett cirkulärt resurshanteringssystem är produktionen av biogas från biologiskt avfall. Syftet med denna rapport är att bidra till expansionen av i huvudsak den småskaliga biogasproduktionen genom att identifiera kriterier som kopplar minskning av partikelstorlek med energibalansen över biogasproduktionssystemet. Genom att göra detta hoppas vi kunna hitta den optimala partikelstorleken för sönderdelning av substratet. För att uppnå detta gjordes en studie över biogasprocessen och de tillgängliga substraten samt sönderdelningsteknologierna. Denna studie visade att halm, gödsel och utsorterade grödor var några av de huvudsakliga intressanta substraten och att mekanisk sönderdelning är det som främst är lämpligt för småskalig biogasproduktion. Från detta kunde den optimala partikelstorleken identifieras genom att jämföra energin från det ökade biogasutbytet med energiförbrukningen av sönderdelaren, specifikt för substratet halm och sönderdelningsteknikerna hammarkvarn och knivkvarn. Detta resulterade i en optimal partikelstorlek för knivkvarn på 0,26mm och för hammarkvarn på 1,59 mm, dock visade känslighetsanalysen att förändringar i energibalansen kunde ändra hammarkvarnens optimum till en betydligt större partikelstorlek. Även om resultatet tydligt visar att knivkvarnen är överlägsen när det kommer till energieffektivitet finns det flera andra faktorer som påverkar vilken metod som blir mest effektiv för olika förhållanden och substrat, där de två främsta faktorerna är teknologins robusthet och substratets egenskaper som fuktighet och struktur. Det är av yttersta vikt att ökningar i effektivitet som den nämnd ovan görs för att ge biogas en möjlighet att slå sig in på bränsle och energimarknaden samt möjliggöra det till att bli ett viktigt bränsle i framtiden.<br>With the growing threats from climate change it is vital that we are able to lessen our reliance of fossil fuels and start using more renewable energy sources. One of these renewable energy sources which brings us closer to a circular resource management system is the production of biogas from biological waste. The purpose of this report is to help the expansion of mainly the small-scale biogas production technology through identifying criteria connecting size reduction to the energy balance of the biogas production system. By doing this we hope to find the optimal particle size reduction of the substrate. To achieve this, a study was done to map the biogas process and find out which substrates and size reduction technologies are currently available. The study concluded that wheat straw, manure and sorted out crops where some of the main substrates of interest and that mechanical size reduction is most suitable for small scale biogas plants. From this the optimal particle size could be found through comparing the energy from the increase in biogas yield with the energy costs of the size reduction equipment specifically for the substrate wheat straw and the mechanical size reduction technologies hammer mill and knife mill. This resulted in an optimal particle size through knife milling of 0.26 mm and by hammer milling 1.59 mm, although the sensitivity analysis showed that changes in the energy balance could shift the optimum of the hammer mill closer to a significantly larger particle size. Even though the results clearly show that knife mills are superior when it comes to energy efficiency there are several other factors that affect which method is most efficient for different substrates and conditions, with the two main being the robustness of the technology and the characteristics of the substrate such as moisture content and structure. Increases in efficiency like, the one mentioned above, is done to give biogas a fighting chance on the fuel and energy market and enable it to become one of the important fuels of the future.
22
Troskialina, Lina. "Improved performance of solid oxide fuel cell operating on biogas using tin anode-infiltration." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6790/.
Full textAbstract:
This work presents a novel method of Sn-infiltration on SOFC anodes for SOFC operation in biogas dry reforming. Using commercially available NiYSZ-based anode supported half cells with hand-painted LSM/YSZ cathode layers, Sn-infiltrated NiYSZ SOFCs containing different amounts of Sn were manufactured. These SOFCs were tested for their electrochemical performance and quantity of deposited carbon during operation on simulated biogas of 1:2 volume ratio of CO2:CH4 without humidification but with 25% Helium added to the feed stream to enable measurements of the fuel cell outlet gas composition using a quadrupole mass spectrometer. Most of the SOFCs were tested in biogas for 1 day (22 hours), but several cells were tested for 6 days (150 hours) to evaluate performance degradation. The electrochemical performance tests at 750 oC showed that with H2 as fuel the non-infiltrated NiYSZ SOFCs were able to reliably generate a moderate level of current of 350 mA cm-2 at 0.7 V; however when simulated biogas was introduced, current dropped significantly to 90-200 mA cm-2. Contrary to non-infiltrated cells, a series of Sn-infiltrated cells under the same operating conditions performed equally well both on H2 and biogas producing 310 to 420 mA cm-2 at 0.7 V. Several cells showed stable electrochemical performance over 150 hours of operation both on H2 and biogas. Using Temperature Programmed Oxidation (TPO), both Sn-infiltrated and non-infiltrated SOFCs showed low quantities of carbon formed during 22 hours operation on biogas. Visual observation and SEM images of the anode surface after 150 hours operation on biogas showed no sign of deposited carbon. The conclusion is that Sn-infiltrated NiYSZ-based SOFC can be operated on simulated biogas with significantly higher electrochemical performance and low carbon deposition, given the anode is adequately modified.
23
Akhand, Md Moniruzzaman, and Blancas Abraham Méndez. "Optimization of NMMO pre-treatment of straw for enhanced biogas production." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16930.
Full textAbstract:
Modern society depends on fossil fuels to fulfill the increasing energy demand, which could cause further damages in the environment. Therefore, it is mandatory to develop technologies for the production of efficient alternative renewable energy sources, like biofuels. Agricultural waste streams, such as wheat straw, produced in larger amount can be utilized for these purposes, and can be used as raw materials for both ethanol and biogas production. However, the compact structure of lignocelluloses present in these materials makes their biological degradation difficult.In order to enhance the biogas production, wheat straw milled to 2mm size was pretreated with N-methylmorpholine-N-oxide (NMMO) at 90°C for 7-30 hours in this study. 90°C was applied as treatment temperature for the treatment to be able to investigate if the district heating system could be utilized in the treatment process in the future. The effects of the different pretreatment conditions were then evaluated by running batch anaerobic digestion assays for 45 days at 55°C.The best result was achieved after 7h treatment, leading to 0.47 Nm3/kg VS of straw methane production, corresponding to an increase by 47% compared to methane production obtained for the untreated straw.Furthermore, it was possible to recover up to 91.33% of the straw after the NMMO pretreatment. There were no significant changes in the chemical composition of the straw caused by the treatment, however structural analyses, like FTIR for the determination of crystallinity and and Simon Staining for the determination of porosity of the material showed that the crytallinity decreased, while the porosity increased as results of the treatment.Soaking in water for 72h prior to NMMO treatment was also applied to see whether it can improve the diffusion of NMMO into the material, but without success, due to the dilution of the treatment chemical caused by the soaking. The findings made during the experimental stage indicated that it is possible to run the NMMO pretreatment at an industrial temperature, further evaluation for the economical feasibility of this treatment method is however needed in the future.<br>Program: MSc in Resource Recovery - Industrial Biotechnology
24
Prokhorova, Anna [Verfasser], and J. [Akademischer Betreuer] Gescher. "Steering biogas performance by implementation of bioelectrochemical cell (BEC) technology / Anna Prokhorova ; Betreuer: J. Gescher." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1116427591/34.
Full text
25
Awasume, Ignatius Ekwe, and Abel Prince Jabakumar Sathiyaraj. "Optimization of Pre-hydrolysis Conditions for the Production of Biogas." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16495.
Full textAbstract:
Hydrolysis and solubilisation of organic material is known to be the rate limiting step during anaerobic digestion. In this study, the effect of pre-hydrolysis was investigated. The substrate had a composition of the following wastes streams: fish and slaughterhouse waste, cleaning waste, doggy meat, doggy sludge, doggy dry food, mink (fur), Norway slurry, SOR2-Industrial waste, and municipal solid waste (MSW) from households in Borås community.Analyses were made on two batches of experiments performed at two different mesophilic temperature conditions; 34 0C and 42 0C and with or without the addition of mesophilic sludge obtained from a waste water treatment plant. One of the substrate maintained the original carbon/nitrogen (C/N) ratio, and for the other substrate the carbon nitrogen ratio was then slightly increased by adding 7.98g of special shredded paper which contains 82% volatile solids (VS). The experiments were run for 7days with samples collected regularly after 0 day, 4 days, 5 days, 6 days and 7 days retention time. Chemical oxygen demand (COD), pH, total nitrogen, and volatile fatty acids (VFAs) as process indicators were analyzed.The results showed that at 42 0C the rate of hydrolysis was faster with a higher COD release and removal. The optimum retention time for hydrolysis was 4 days and any longer time caused some of the carbon to be lost to carbon dioxide. The effect of adding mesophilic sludge had no significant effect. An increased C/N ratio resulted in a balanced system with lower VFAs produced compared with that from the original substrate mixture.<br><p>Acknowledgements: The authors are heartily thankful to their supervisor Ilona Sárvári Horváth whose guidance and support from the initial to the final level of this thesis work enabled us to gain a deeper understanding of the project.</p><p>We equally extend our sincere gratitude to the following persons who never ceased in helping until this work was complete.</p><p>Solmaz Aslanzadeh: For sharing her precious time and positive insight in coping with associated challenges of the project.</p><p>Hanson Jonas: Your assistance and patience over our laboratory experiments given the limited resources vis-a-vis students demand is quite reminding and saluted.</p><p>The support team at Sobacken Biogas plant: Your concern and timely assistance beginning from the supply of the substrate and the opportunity granted us to use your laboratory station greatly ensured results validation.</p><p>Program: MSc in Resource Recovery - Sustainable Engineering</p><p>Program: MSc in Resource Recovery - Industrial Biotechnology</p>
26
Lindén, Maja. "Matrester blir biogas : En interaktiv informationsfilm för barn." Thesis, Mälardalen University, School of Innovation, Design and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-5563.
Full textAbstract:
<p>Arbetet har bestått i att utföra en informativ webguide över en anläggning i Västerås som tillverkar biogas och biogödsel av matrester. Beställaren heter VafabMiljö. Mina kontaktpersoner, Caroline Eklöv och Åsa Lindén, är skolinformatörer. Guiden ska publiceras på VafabMiljös hemsida för skolklasser på Internet och där fungera som en förlängning av informatörernas arbete i skolorna. Målgruppen är barn i årskurs 3-5. En uttalad förebild fanns: Göteborgsföretaget Gryaabs guide om vattenrening Vart tar bajset vägen? (http://www.gryaab.se/).</p><p> </p><p>Under arbetets gång har design- och funktionsbesluten fattats med stöd av:</p><ul type="square"><li>Intervju med kund och besök på anläggningen</li><li>Omvärldsanalys, mestadels på Internet</li><li>Egna erfarenheter</li><li>Kontinuerliga utprovningar</li><li>Litteratur</li></ul><p> </p><p>Arbetet har utförts i Illustrator och Adobe Flash.</p><p> </p><p>Eftersom det var många delar i processen som skulle illustreras var det nödvändigt att arbeta snabbt. Önskemål från kunden var att låta enkelt, tydligt och roligt gå före korrekt återgivning. Detta har lett till ett manér där jag använt mig mer av symboler än verklighetstrogen avbildning. I rapporten beskrivs intressanta designbeslut där min målsättning varit att låta begriplighet gå före realism.</p>
27
Alander, Johanna, and Adam Nylin. "Feasibility study for producing and using biogas in Chisinau, Moldova." Thesis, Linköpings universitet, Industriell miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157694.
Full textAbstract:
More and more people live in cities, cities that both present opportunities, in terms of potential sustainable growth and challenges, for example regarding insufficient infrastructure and waste management. There are several examples on initiatives to make cities reach their sustainability potential; one is to turn municipal organic waste, MOW, and sewage sludge into biogas and use it to produce electricity and/or heat or to upgrade it to biomethane and use it as a fuel in for example public transport or feed it to a gas grid. This study has focused on the potential and feasibility of producing and using biogas/biomethane as well as the remains from the production process, called digestate, in Chisinau, the capital of Moldova. For the most feasible options an indication of the environmental improvement and economic performance was also estimated. The study included biogas produced from municipal organic waste, sewage sludge and methane collected at landfills. For the areas of use, electricity or heat produced from biogas was included as well as using biomethane in public transport or feeding it to the gas grid and to use the digestate as biofertilizer. Since multiple factors needs to be considered in order to adequately assess the potential and feasibility a multi-criteria approach was used for developing a framework based on an early assessment tool for biomethane solutions in the urban context. In summary it is indicated that there are good conditions for biogas production in Chisinau with biogas production from sewage sludge being included in the ongoing rehabilitation of the largest wastewater facility and methane collection from the largest landfill historically being part of the operations and planned (although not confirmed) to soon be part of these again. However, the largest potential is for municipal organic waste where the main impediments relates to financial issues and to some extent legislation that indirectly favour short term landfilling. When investigating the possible use of the digestate as biofertilizer the outlooks are considerably less promising than for the supply side. Despite the fact that the law explicitly allows the use of digestate (both from MOW and sewage sludge) the lack of knowledge within the farmer community result in a low or non-existent customer demand. Regarding the possible use of biogas/biomethane it was concluded that electricity production is the most feasible option and heat generation placing as the second most feasible. Feeding the gas to the grid appears more difficult and the least likely option is for the biogas to be used within public transport. Overall it is in general technically possible to use the gas in terms of infrastructure and there is some demand, especially for electricity and heat. The biggest inhibitory factors are rather institutional since biogas in general is overlooked or not prioritized in the strategies leading to a shortcoming in economical instruments or funds and to some extent in the legislation. This thesis is complemented by an executive summary with the same name, both in English and translated to Romanian.
28
Trentin, Vânia Maria. "Aplicação da tecnologia de membranas poliméricas para purificação de biogás." reponame:Repositório Institucional da UCS, 2017. https://repositorio.ucs.br/handle/11338/3383.
Full textAbstract:
Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-12-14T15:43:27Z
No. of bitstreams: 1
Dissertacao Vania Maria Trentin.pdf: 202884 bytes, checksum: 59d062f3025b704762c62d6d9d087ab3 (MD5)<br>Made available in DSpace on 2017-12-14T15:43:27Z (GMT). No. of bitstreams: 1
Dissertacao Vania Maria Trentin.pdf: 202884 bytes, checksum: 59d062f3025b704762c62d6d9d087ab3 (MD5)
Previous issue date: 2017-12-14<br>Centro de Pesquisa e Desenvolvimento Leopoldo Américo Miguêz de Mello, CENPES.
29
Lester, Daniel Warren. "Creation of a semiconductor system for the removal of volatile organic compounds from biogas." Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/48135/.
Full textAbstract:
This thesis is concerned with the preparation, and subsequent investigation of, titanium dioxide (TiO2) nanomaterials and their ability to remove phenol from gas streams for application towards the abatement of polluted land fill gas (LFG). Using the well documented ability of TiO2 to excite an electron by UV light, phenol was removed from gas streams to investigate the efficacy of TiO2 nanomaterials. Phenol was chosen as a representative VOC but the catalysts were proven to also remove four other organic compounds during gas phase photocatalysis. It was found that in loadings of 1 mol % the degradation of phenol could be increased relative to pristine TiO2 nanofibres. The activity of six metal oxide dopants were fairly compared to one another where it was found that cobalt doped TiO2 showed very high activity, more so than P25 powder. Furthermore, mono-metallic cobalt nanomaterials were shown to degrade phenol in the gas phase, however, more studies are required on these materials. Supports for TiO2 were investigated in order to provide a more practical catalyst for industrial continuous flow reactors. These included novel zeolite:titania composites which were fibrous, non-woven mats of these materials were prepared by electrospinning and were shown to effectively remove phenol from polluted gas stream.
30
Öhman, Axel, and Bill Edwall. "Opportunities for the Jatuwa community biogas plant : An energy demand survey and a field site examinationMinor Field Study." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-233837.
Full textAbstract:
De klimatförändringar som idag orsakar allt större problem för länder i Himalayaregionen har ökat beslutsfattares medvetenhet kring konsekvenserna som de ökande temperaturerna för med sig. När människor konsumerar energi från fossila bränslekällor ökar koncentrationen av bland annat koldioxid i atmosfären vilket bidrar till den växthuseffekt som sakta värmer upp jordens klimat. Detta påverkar ekosystem och ökar risken för naturkatastrofer. Nepal är ett av länderna som ser konsekvenserna av den globala uppvärmningen från nära håll och landet satsar därför på att utveckla energisektorn genom implementeringen av fossilfria energislag. En av de mest framgångsrika satsningarna är användandet av biogasteknologi. Idag har över 350 000 småskaliga biogasanläggningar installerats över hela landet. Alternative Energy Promotion Centre (AEPC), den verkställande myndighetsorganisationen för främjande av ren och hållbar energi satsar nu på att utveckla den storskaliga biogassektorn för att öka landets inhemska och hållbara energiutvinning. Shree Krishna Gau Sewa Sadan (SKGSS) är en hinduisk stiftelse belägen i byn Jatuwa i sydöstra Nepal vars syfte är att ta hand om och betjäna kor, djur som inom hinduism är betraktade som heliga. Stiftelsen siktar nu på att bli ekonomiskt självförsörjande genom att sälja biogas och rötslam från en nyligen byggd biogasanläggning till närliggande hushåll. Gasen ska produceras från dynga insamlat från stiftelsens kor och distribueras genom ett gasnät som ännu inte är byggt. Syftet med denna studie var att utreda möjligheterna för SKGSS att framgångsrikt driva biogasanläggningen och fokuserade på två områden som var av intresse för AEPC, projektets huvudsponsor. Det första var att primärt beräkna hushållens energibehov för matlagning, deras nuvarande energikostnader för matlagning och deras inställning att byta till biogas som matlagningsbränsle för att assistera planeringen av det framtida gasnätet. Det andra var att lokalisera och identifiera potentiella förbättringsområden inom biogassystemet och baserat på detta ge förslag på huvudsakligen tekniska förbättringar som kan hjälpa SKGSS att framgångsrikt driva biogasanläggningen. Studien genomfördes med hjälp av en litteraturstudie, semi-konstruerade intervjuer, enkätundersökning av hushållen och en inspektion av biogasanläggningen. Enkätundersökningen visade att hushållens intresse att byta till biogas är stort. De flesta var dessutom villiga att betala för att anslutas till gasnätet. Den positiva inställningen till biogas härrör möjligen delvis från en ökad medvetenhet kring klimatfrågor samt energisäkerhet. Undersökningen visade även att det närliggande området inte är en trolig marknad för försäljning av rötslam. Dock är Nepal en växande marknad för organiskt och högkvalitativ gödsel så möjligheterna för en lyckad försäljning av rötslam är ändå stora. De primära beräkningarna visade att anläggningen med dess idag tillgängliga mängd organiskt material inte kan förse mer än 50 hushåll med biogas. Vid planläggningen av gasnätet måste dock beräkningar baserade på faktiska mätningar av biogassystemet göras. Denna studie rekommenderar även ett antal förbättringar av biogassystemet som skulle kunna hjälpa stiftelsens biogasanläggning att fungera bättre.<br>As climate change becomes an ever-bigger issue for countries in the south-Himalayan region, policy makers become more aware of the problems associated with increasing temperatures. As countries consume more energy extracted from fossil fuels the climate becomes warmer, affecting ecosystems and increasing the risk of natural disasters. Nepal is one of the countries seeing the effects of global warming from close range and the country is now seriously aiming to develop its energy sector through the implementation of sustainable energies. One of the more successful stories of the Nepali energy sector is the implementation of biogas technology. As of today, more than 350 000 small scale biogas systems for single household use are operating all over Nepal. The Alternative Energy Promotion Centre (AEPC), the focal governmental agency for the promotion of sustainable and clean energy, is now aiming to develop the large-scale biogas sector. This would increase the amount of domestic sustainable energy as well as the country’s energy security. The Shree Krishna Gau Sewa Sadan (SKGSS) is a Hindu trust located in south-eastern Nepal with the purpose of taking in and serving cows. It now aims to become economically self-sufficient by selling biogas and slurry produced from a newly constructed large-scale biogas plant to the nearby community households. The biogas will be produced from cow dung collected on the property and distributed to the households through a gas grid that is yet to be designed and built. The purpose of study was to investigate the opportunities for the trust to successfully operate the biogas plant and was focused on two areas of interest to the AEPC, which is the key sponsor of the community biogas project. The first was to primarily calculate the energy cooking demand of the nearby households, their current cost of cooking and their attitude towards a switch to biogas usage which would assist the planning of the future gas grid. The second was to localize and identify potential areas of improvements within the biogas system and based on that offer suggestions of improvements focused on technical aspects that would help the SKGSS to successfully operate the biogas plant.The study was conducted using a literature study, semi-constructed interviews, household surveys and on-site inspections of the biogas plant. The household survey showed that the nearby households’ interest in switching to biogas is high. Most of the households also showed to be willing to pay extra money to be connected to the biogas grid. The positive attitude towards biogas partly stems from a raised awareness about climate issues as well as increased security in energy security. The survey also showed that the nearby urban and semi-urban community is not a viable market for the produced slurry. However, Nepal is a big and growing market for organic high value fertilizer so the potential of a successful sale of slurry is still high. The primary calculations show that with the feedstock available, the community biogas plant cannot suffice more than 50 households’ energy demand for cooking. When designing the gas grid, proper calculations based on actual measurements of the biogas system need to be done. This study also recommends various improvements of the biogas system that will help the SKGSS biogas plant to operate successfully.
31
Lundmark, Olle. "Evaluation of mixed integer linear programming solvers when applied to a biogas reactor system model." Thesis, Umeå universitet, Institutionen för datavetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155344.
Full textAbstract:
Optimization of a biogas reactor system, to maximize its profits, is a natural step to become a more competitive electricity source. This is done by first formulating mixed integer linear program (MILP), of an abstract biogas reactorsystem, which is then implemented with parameters to simulate a real biogas reactor system. Then to solve a MILP problem, a solver is used. Depending on what solver is used to solve the problem, the run-time and solution may differ a lot. That is the reason why FarmBioTech AB is interested in the evaluation of the solvers Cplex, Gurobi, Glpk, and Cbc when applied to a biogas reactor system model. The solvers are evaluated by checking if they manage to find feasible solutions that are at most 1% from the optimal solution within a run-time limit of one hour. Both Gurobi and Cplex managed to find quality solutions within the given run-time limit, while Glpk and Cbc did not.
32
Mushtaq, Maryam. "Pressurissed carbon dioxide as a means of sanitising sewage sludge and improving biogas production." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/355975/.
Full textAbstract:
The research reports on the potential for CO2 pressurisation as a means of enhancing biogas production in the anaerobic digestion of co-settled sewage sludge, a technique reported in the commercial literature as showing great benefits. The possibility of using this technique to reduce the number of faecal indicator bacteria is also explored, as an alternative means of complying with the UK water industry's Safe Sludge Matrix. Initial research using pure cultures of both E. coli (a strain isolated from sewage sludge) and Salmonella enterica showed that the results from different methods for isolating, recovering, resuscitating and enumerating E. coli were comparable. Further testing using heat stressed and unstressed E. coli showed the advantages of resuscitation and the MPN technique with 2-stage incubation was therefore used in the experiments to maximise the recovery of damaged but viable cells. The results for pure cultures showed conclusively that under the conditions of time and pressure used CO2 pressurisation and rapid depressurisation could cause irreversible cell damage and loss of viability in both test strains. The effect was reproducible and a time-pressure relationship was established for the apparatus used. It was shown, however, that the sanitising effect was influenced by culture volume, probably as this affected mass transfer of CO2 and hence its penetration into the cells. This finding may limit the practical application of the approach and further work is needed to establish design parameters and develop reactor systems to overcome this issue. Even under the favourable conditions used, exposure times required for 6 log reduction were too long for commercial application. Optimisation of the pressurisation vessel design may improve this and should be a focus of any future investigations. Batch and semi-continuous anaerobic digestion tests with co-settled sewage sludge were carried out to ascertain the effect of pressurised CO2 treatment on biogas production. These showed conclusively that the treatment did not improve either biogas productivity or specific methane yield. Experimental work also showed that even treatment conditions which gave an 8 log reduction in E. coli in pure culture were ineffective in reducing the number of indigenous E. coli in the sludge, or of S. enterica when added to a sewage sludge matrix. These findings led to further investigation of the effects of the size of pressure vessel and sample used. The results showed that this was an important factor, but could not fully explain the lack of performance in comparison with pure culture. It was concluded that the sludge matrix itself must play a role in protecting the microbial consortia from the effects of pressurised CO2. The exact reasons for this were not discovered but may be due to the effect of dissolved compounds present in the sludge and/or the structure and nature of the sludge flocs themselves.
33
Wollak, Birte. "Determination of the methane potential of blue mussels." Thesis, Linnéuniversitetet, Institutionen för bygg- och energiteknik (BE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-27098.
Full textAbstract:
The aim of this study was to evaluate the methane potential of 35 kg of blue mussels in a batch amanaerobic two-stage dry digestion system (pilot-scale), which consists of aleach bed reactor (LB) and an up-flow anaerobic sludge blanket reactor (UASB). We monitored the process daily by measuring temperature, pH, COD, VFA, NH4+ gas flow rate and gas content. The temperature was approximately 30 C in the LB and 36 C in the UASB reactor. The applied OLR was 1.5 g COD/l*d. After 37 days process run, we obtained a total methamne yield of 0.64 Nm3 respectively 0.29 Nm3/kg VS, of that 70% in the LB reactor and 30% in the UASB reactor.
34
Sund, Emil. "Small-scale biogas : A techno-economic comparison of Internal Combustion Engines, Micro Gas Turbines and Stirling Engines." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280467.
Full textAbstract:
Gas driven power generation is expected to increase in the near future due to significantly lesser environmental impact than oppose to conventional fuels like coal and oil. Today, Natural Gas (NG) is the dominant product on the market and biogas, which originates from degradable organic waste, has not reached its full market potential due to bottlenecks in utilization. Biogas often contain less methane and more trace elements than NG and is therefore seldom feasible to use in power generation. Especially at small biogas flows, the equipment needed for cleaning of the gas is often too expensive to consider. The biogas used in this study was assumed to contain 55 % methane with trace elements of hydrogen sulfide (H2S), moisture and Siloxanes. One way to surpass this cleaning step is to use externally fired machines, like Azelio’s 10 kWel GasBox which is a Stirling engine coupled with a gas preheater and combustion chamber. A model was developed which analyzed both costs and operation parallel with the two most market mature options, Internal Combustion Engines (ICE) and Micro Gas Turbines (MGT), which indicated that the GasBox is competitive at small biogas flows translating to less than 100 kWel output due to this. A market analysis and screening with a Multi-Criteria Analysis (MCA) was performed to locate markets for which the demand for a product like the GasBox existed. The study showed that there is an estimated demand for around 53 000 units in the German agriculture, which is one of the worlds most innovative markets when it comes to both biogas and renewable energy in general. Further on, it was discussed what is needed from both understanding the market but also the technologies involved for succeeding on the market.
35
Lau, Chia Sheng. "Biogas upgrade through exhaust gas reforming process for use in CI engines." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3472/.
Full textAbstract:
Biogas is not ideal for combustion in diesel engines mainly due to its low energy content. The upgrading of biogas into high quality syngas through catalytic reforming reactions was investigated. Studies on the effect of temperature, space velocity and O\(_2\)/CH\(_4\) molar ratio on various basic biogas reforming processes were done. The dry reforming of biogas was found to be active at high reactor temperatures with syngas production and reduction of carbon dioxide. The promotion of simultaneous dry and oxidative reforming by adding oxygen improves syngas production at conditions of low temperature and high space velocity. Subsequently, the biogas exhaust fuel reforming process was done by feeding real engine exhaust together with biogas into the reforming reactor. Reforming process efficiency of 95% (ratio of energy content of reformate to biogas) was achieved at high space velocity and high content of steam in exhaust at medium engine load (300°C exhaust temperature). Further improvement was observed when reformed exhaust gas recirculation (REGR) was applied due to increased exhaust steam content in the engine – reactor system which promoted the endothermic steam reforming reaction. Moreover, improved engine thermal efficiency and lower emissions were found during reformate gas-diesel operation compared to biogas-diesel operation.
36
Sylveson, David. "Uppföljningsanalys av en biogasanläggning : Sammanställning av driftdata från More Biogas Smålands AB." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-88894.
Full textAbstract:
Driftdata från More Biogas anläggning i Kalmar har sammanställts och analyserats för att föreslå förbättringar i sammansättningen av den inkommande substratmixen för att öka gasproduktionen. C/N kvoten för den inkommande substratmixen är låg då en optimal C/N kvot är mellan 20 till 30. För att få upp den totala C/N kvoten till 15 behövs 27 ton halm i månaden tillsättas och 80 ton för att få upp den till 20. Det är även bra att tillsätta halm från ströbädd eller hönsgödsel som har en hög TS-halt eftersom det finns möjlighet till en ökad VS-belastning i processen.Slakteriavfall gav en positiv effekt på gasproduktionen och efter en jämförselse av två tidsperioder gav resultatet att gasproduktionen ökade med en MWh per ton TS av tillsatt slakteriavfall.Det finns inget tecken på att processen är hämmad av de inhiberande parametrarna eftersom inte gasproduktionen minskade de månader då de inhiberande parametrarna var högre.
37
Tilli, Paola. "Production, characterization and modeling of hollow fiber membranes for biogas purification." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textAbstract:
One type of technology for biogas purification which has experienced substantial growth during past decades is membrane-based technology which presents the advantage of high energy efficiency, simplicity in design and environmental compatibility. The market for CO₂ is dominated by polymeric membranes due to their relatively low manufacturing cost. In this work, the performance of different P84 hollow fibers membranes for CO₂/CH₄ separation is investigated. Different spinning parameters are studied on their effect on gas separation performance of the produced fibers. The attention is focused on air gap length and spinning temperature, since they both affect the formation of the selective layer during the spinning process. Scanning Electron Microscopy (SEM) is used to investigate the morphological characteristics of the developed fibers. Permeation rates of CO₂ and N₂ are measured using the pressure increase method. The achieved ideal selectivity was 30/40 for CO₂/N₂ separation, while permeances are quite low. The permeance of CO₂ through asymmetric hollow fibers increases with pressure because of plasticization. Both gases permeance increases by increasing the air gap and higher spinning temperatures lead to lower permeances. Finally, NE-LF model is used to calculate CO₂ and CH₄ solubility and CO₂/CH₄ solubility selectivity in P84. Large deviation from ideal conditions is predicted underlining a marked competition which affects more CH₄ than CO₂ and results in a real solubility selectivity higher than the ideal one. By considering that real mixed gas perm-selectivity generally presents negative deviation, it follows that diffusivity of CH₄ in P84 is enhanced in presence of CO₂ lowering the diffusivity-selectivity.
38
Aslanzadeh, Solmaz, and Peyruze Özmen. "Biogas production from municipal waste mixed with different portions of orange peel." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19554.
Full textAbstract:
Orange cultivation is a huge industry which increasing for each year. By the year 2010 theorange production of the world is expected to reach 66.4 million tons per year. Most of theoranges are used for orange juice production. Consequently, a large amount of organic wastes,including seeds, segment membranes and peel, counting up to half of the weight of usedoranges, are generated As alternatives to land filling and incineration, source separation andcomposting together with biogas production are being considered as suitable methods fortreating this fraction of wastes, because it holds a high amount of organic materials in form ofvaluable carbohydrate polymers. However, the presence of peel oil, limonene, known to haveantimicrobial effects, has showed to be a strong inhibitor for the biogas producingmicroorganisms. Therefore the orange peel waste (OP) was mixed with the organic fraction ofmunicipal solid waste (MSW) in this study to keep the concentration of this inhibitorycompound at low level.Based on the results from previous batch experiments, this study was performed in order toconfirm and develop the possible use of orange peel waste in biogas production. Since thebatch experiments showed that the methane production was not affected, when a mixture of70% MSW and 30% OP (calculated on the basis of volatile solids (VS) content added) wasused as substrate, a continuous anaerobic digestion experiment was performed using the samemixture of MSW and OP as a substrate in this study. Furthermore, a reactor utilizing onlyMSW was used as a control. Both reactors were operated during 35 days at thermophilicconditions (55ºC), with an organic loading rate of 3gVS/L/day and a hydraulic retention timeof 21 days. The methane production was around 0,5 Nm3/kgVS/day in both reactors duringthe first period of operation. However, the production of methane started to decrease after 20days followed by a sharp decrease during the last 5 days in the orange peel-containing reactor.Furthermore, a steadily increase (from 4,85g/L to 6,51g/L) in the total content of volatile fattyacids (VFA) could be observed here, while the total content of VFA in the control reactorremained at low levels (0,84g/L). A second experimental set up using a decreased amount ofOP (20% OP and 80% MSW) in the substrate mixture and operating at the same conditions sthe previous experiment was also performed and showed similar trends in the results. Thefailure of the process can be explained by inhibition in the system, which led to theaccumulation of VFA’s resulting in a decreased and finally no methane production. Thisinhibition might be caused by the accumulation of the inhibitory compound, limonene,presented in the orange peel waste. Therefore some treatment of the OP is necessary prior todigestion to avoid this inhibition. Batch digestion of treated vs untreated OP showed that themethane production of treated OP could be increased to 0,628 Nm3/kgVS compared to that of0,408 Nm3/kgVS from the untreated sample. Further investigations utilizing this treated OPfraction in continuous biogas process are necessary in the future.
39
Khorshidi, Nasrin, and Beyza Arikan. "Experimental Practice in order to Increasing Efficiency of Biogas Production by Treating Digestate Sludge." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18706.
Full textAbstract:
According to national and international policies in order to protect environment regarding renewable sources of energy, biogas is one of the best alternative to reduce waste and pollution and getting energy. Biogas is the gas that is produced by some kinds of microorganisms in anaerobic condition from organic waste treatment. Technology of biogas plants is varies and there is no standard procedure that is applicable worldwide. Methane (biogas), which is produced from wastes and it is known widely since 1973. By organic waste degradation methane is produced and waste volume will be reduced. Some surveys prove that during anaerobic digestion only 50% of organic matter is degraded. Anaerobic degradation has some steps that are hydrolysis, acidogenesis, acetogenesis and methanogenesis. Since hydrolysis is rate-limited step it can be improved by some pretreatment and some action like improving monitoring system can show that the efficiency of biogas will increase. There are three main pretreatment methods. During this study digestate sludge from different waste treatment plants were pretreated. First experience was pretreating digestate sludge from Sobacken, Falköping, Västerås by Enzyme Addition (Cellolase) and the measuring of biogas (methane) has done by Gas Chromatograph (GC). Second experience was pretreating digestate sludge by Acid (Sulfuric acid). The data of those measurements are shown that the amount of biogas was increased two times in the case of Västerås by enzyme addition, which is about 70% of theoretical expectation of this pretreatment and pretreating digestate sludge of Sobacken by acid pretreatment could increase the amount of biogas two times as well that was about 60% of theoretical estimation. By proper gas chromatograph and choosing one kind of waste and pretreating that by just one kind of pretreatment in each experience and following the results and going further the biogas efficiency will increase significantly because still 50% organic matter is inside the digester.<br>Uppsatsnivå: D
40
Stoddard, Isak. "Communal Polyethylene Biogas Systems : Experiences from on-farm research in rural West Java." Thesis, Uppsala University, Global Energy Systems, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-131203.
Full textAbstract:
<p>In Lembang, a farming community on western Java, family-sized, plug-flow, polyethylene biogas systems fed with cow dung, are being used as an integrated solution to issues related to energy, agriculture and waste management. Through simple, on-farm research and observation, a number of key problems have been addressed and improvements made to the design. Due to the large supply of cow dung in the area, and the potential to spread the benefits of the technology beyond the homes of dairy farmers, the feasibility of developing a communal, polyethylene biogas system for several households, has been investigated. Experiments on small model-digesters were combined with observations of full-scale biogas systems in use. Measurement equipment and techniques were constructed and developed, in order to measure biogas production and other relevant process parameters. Results indicate that a communal system can be an appropriate choice, but only under a certain set of circumstances.</p>
41
Bolin, Lisa, Hui Mien Lee, and Mattias Lindahl. "LCA of Biogas Through Anaerobic Digestion from the Organic Fraction of Municipal Solid Waste (OFMSW) Compared to Incineration of the Waste." Linköpings universitet, Industriell miljöteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51291.
Full textAbstract:
Production of biogas through anaerobic digestion (AD) from the organic fraction of minucipal solid waste (OFMSW) was compared to incineration of the waste. At the moment, almost all of the OFMSW in Singapore is incinerated. Three different scales of biogas plants were compared to incineration: one large-scale biogas plant that can treat half of all OFMSW in Singapore; one medium- scale biogas plant about 15 times smaller than the large one; and one small-scale biogas plant that can treat waste from e.g. a shopping centre or food centre. Two alternatives for utilization of the biogas were also compared, generation of electricity and the use of the biogas in heavy vehicles. The combination of the different scales and the different utilization gives the six different scenarios. By using life cycle assessment (LCA) the different scenarios were compared in terms of global warming potential (GWP), acidification, eutrophication, energy use and land use. The results show that biogas production creates less environmental impact than incineration. The use of the gas as a vehicle fuel creates a bigger decrease of GWP, acidification and eutrophication than when using the gas for electricity generation. The prevention of leakage of biogas during production and upgrading is crucial for the environmental impact on GWP. A leakage of only a few percent of the produced gas will lead to a loss of all the gain in saved GHG-emissions.
42
Hasan, Md Rejaul. "Feasibility study to design a Biogas-Photovoltaic hybrid system for electricity generation in vicinity to urban areas in Bangladesh." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-40060.
Full textAbstract:
The world´s future energy generation needs to be sustainable without negative impact on people´s health or on our nature. Within present trends to develop energy scenarios with diminishing use of fossil fuels, nuclear power etc. it seems difficult to meet an increasing need for energy. Incorporation of renewable energy sources within the energy sector could mitigate future energy crises in a sustainable way. Bangladesh is a south Asian developing country with great prospects of renewable energy resources. Severe energy crisis such as shortage on electricity generation over the decades is one of the major problems in the country. This problem could be reduced by introducing renewable energy resources at a large-scale within the power sector. Renewable energy sources are increasingly used due to its availability and it has little negative impact on the environment. Solar energy and biomass are great and valuable resources in the green energy field. In this thesis, a feasibility study of a hybrid renewable energy system, HRES, including biogas fueled internal combustion engines, driving an electrical generator and solar PV in vicinity to urban areas in Bangladesh was analyzed using HOMER software. The HRES system was designed for electricity generation in a community near Dhaka city in the Gazipur district where great resources of solar and biomass are available. In the proposed hybrid system, a 40-kW biogas electric generator is integrated with 80 kW of PV panels and the analysis shows an energy price of €0.1435/kWh.
43
Hagman, Linda. "How do biogas solutions influence the sustainability of bio-based industrial systems?" Licentiate thesis, Linköpings universitet, Industriell miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152878.
Full textAbstract:
Biomass is a valuable and limited resource that should be used efficiently. The potential of replacing fossil-based products with bio-based ones produced in biobased industrial systems is huge. One important aim of increasing the share of biobased products is to improve the sustainability of systems for production and consumption. Therefore, it is important to evaluate what solutions are available to improve the sustainability performance of bio-based industrial systems, and if they also bring negative impacts. The thesis focuses on assessing the role of biogas solutions in developing sustainable bio-based systems. Such assessments are often quite narrow in their scope and focus on quantitative environmental or economic aspects. This thesis aims at also including feasibility related aspects involving the contextual conditions that are assessed more qualitatively. Biogas solutions are identified as a versatile approach to treat organic materials which are generated in large volumes in bio-based industrial systems. The results show that biogas solutions in bio-based industrial systems (i) improve circular flows of energy and nutrients, (ii) are especially viable alternatives when the quality of the by-product streams become poorer, and (iii) may improve the profitability of the bio-based industrial system. To perform better assessments of these systems, it seems valuable to broaden the set of indicators assessed and include feasibility-related indicators, preferably through the involvement of relevant stakeholders as they contribute with different perspectives and can identify aspects that influence the sustainability in different areas. Future studies could benefit from applying those broader assessments on more cases to build on a more generalisable knowledge base.
44
Nyström, André, and Jakob Vilör. "Rening av amin i biogasproduktion : En studie med syfte att undersöka om det går att optimera företaget Puregas Solutions AB uppgraderingsanläggningar för biogas med hjälp av olika reningsfilter samt undersöka hur dessa filter underhålls." Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-64276.
Full textAbstract:
Abstrakt Det förnyelsebara bränslet biogas har fått mer och mer intresse runt om i världen, men för att biogasen ska gå att använda som fordonsbränsle måste den först uppgraderas. I den processen separeras kolväten och andra föroreningar för att metanhalten ska ökas och därmed kommer biogasen att bli optimal för användning i förbränningsmotorer (Enefalk och Ersöz 2016). Syfte med det här arbetet var att undersöka hur bra olika filter kan fungera för att ta bort orenheter från aminen i Puregas Solutions AB anläggningar. När undersökning av olika filter var gjord studerades underhållet för dessa filter. Experimentet utfördes i Puregas Solutions AB verkstad. Där användes ett aminprov från deras anläggning i Sverige för att den var extremt förorenad och därmed var det lättare att se hur bra de olika filtren filtrerar föroreningar. Efter att mottagit provsvaren från DOW Chemical Company sammanställdes analyserna. Provsvaren visade på att de testade filtren inte tog bort orenheter från aminen.<br>Abstract Renewable biogas fuel has become increasingly interesting around the world, however before biogas is used as fuel in vehicles it must first be upgraded. During that process the hydrocarbons and other pollutions are separated to increase the concentration of methane and make the biogas better suited for combustion engines (Enefalk and Ersöz 2016). The purpose of this study was to examine how efficiently different filters can remove impurities from amine at Puregas Solutions AB upgrading plant. After the investigation of the different filters was completed we wanted to further study the maintenance of the filters. Experiments were performed at Puregas Solutions AB workshop, where the amine samples from their plant in Sweden were used to see how well the various filters performed. After receiving the test results from Dow Chemical Company, the results were compiled and they showed that the tested filters did not remove impurities from the amine.
45
Sindall, Rebecca Clare. "Increasing the efficiency of anaerobic waste digesters by optimising flow patterns to enhance biogas production." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5636/.
Full textAbstract:
Anaerobic digestion is used to stabilise sewage sludge and produce biogas. Whilst the need to mix digesters is well-recognised, the level of mixing required and its effects on biogas production are not clear. Here, the effects of mixing speed in mechanically-mixed lab-scale digesters on biogas production are considered. For the first time, positron emission particle tracking was used to visualise flow patterns in lab-scale digesters at different mixing speeds. Computational fluid dynamics models were then built to identify the turbulence characteristics. Four lab-scale digesters were run for four months at different mixing speeds and key indicators of digester stability and microbiological population were recorded alongside gas production. Increased mixing speed leads to higher levels of turbulence and in these digesters, increasing the mixing speed reduces the stability of the methane generation process and accordingly has a detrimental effect on the gas production. Similarly, the abundance of methanogenic communities was adversely affected by increasing mixing speeds. However, the unmixed digester produced less biogas than the digester mixed at a low speed, due to uncontrolled digestion. As such, for these digesters, minimal mixing represents the ideal scenario. By considering the velocity gradient in the digester as a surrogate for turbulence, a threshold of 6 8 s-1 was identified. Below this threshold, increased mixing was beneficial but increasing mixing above the threshold was detrimental to digester stability and gas production.
46
Sadri, Sahar. "Exploring business models for export of environmental technology : Cases from Linkoping city, Sweden." Thesis, Linköpings universitet, Projekt, innovationer och entreprenörskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97718.
Full textAbstract:
At present time, climate and energy issues are important subjects in the international market and environmental technology is a rapidly growing concept. Many companies in Sweden have developed much in-house knowledge in environmental technology. Therefore, they have great opportunity to export. In the sustainability perspective, export has not only benefits in the economic aspect, but also advantages for the environment. Development of appropriate business models is necessary for supporting environmental technology export.In this research an attempt was made to explore business model elements and offerings for export of environmental technology. The relevant theories in environmental technology characteristics, customization, product service systems and business models were used.The case studies included a Swedish municipality-owned company, its subsidiaries and a Swedish private company which was active in export. Empirical data were collected by conducting of interviews. The results reflect the business models and offerings of the studied cases. The analysis of cases provided findings for environmental technologies characteristics which have effect on export business models.Furthermore, six categories for making distinction among different elements of business models in literature were defined in this study. By analysis of the cases a new category which entailed new elements was added as the seventh category. The mentioned categories are useful in business model formulating for export of environmental technology.
47
Khorshidi, Kashani Azar. "Application of Various Pretreatment Methods to Enhance Biogas Potential of Waste Chicken Feathers." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19567.
Full textAbstract:
Chicken feathers are the most abundant keratinous biomass in the world. Disposal of thehuge and increasing volume of waste feathers presents as a major concern for poultryindustry. On the other hand, energy and material recovery of this valuable protein sourceis an important issue for organic solid waste treatment and bioenergy generation.Anaerobic digestion is an environmentally and economically promising alternativeprocess for biogas production of waste feathers.In this study in order to enhance the methane potential of batch anaerobic digestion ofchicken feathers this waste was treated by various kinds of pretreatments includingthermal, thermo-chemical, enzymatic, thermo-enzymatic and chemo-enzymatic methods.Also the effect of different treatment conditions on the methane yield was investigated.As a whole, thermo-chemical pretreatment with lime (Ca(OH)2) rendered the mostsignificant effect on enhancement of the chicken feathers methane potential. In particularlime treated triplicate samples under treatment condition of 40g TS feather/l water, 0.1gCa (OH)2 /g TS feather, 100°C and 30 min produced the highest amount of methane (anaverage maximum volume of 480 Nml/g VS, which is about 96.8% of the theoreticalmethane potential of protein), during 50 days of anaerobic incubation. Increasing theoperational parameters such as feather concentration, lime loading, temperature andreaction time improved the feathers solublisation resulting in a higher soluble chemicaloxygen demand (SCOD) concentration of the samples but inserted negative impacts onthe anaerobic digestion performance. Although other pretreatment methods improved theSCOD concentrations of the feathers too, compared to the lime treatment those methodsdidn’t show considerable effects on the enhancement of methane yield from the chickenfeathers. Thermo-enzymatic, enzymatic, and thermal pretreated triplicate samplesproduced an average maximum of 185 Nml/g VS, 154 Nml/g VS, and 143 Nml/g VS(37.3%, 31%, 28.8% of the theoretical methane potential) respectively, during 33 days of50 days of anaerobic incubation. Especially, chemo-enzymatic pretreated sample showednegative methane potential of only 41 Nml/g VS, i.e. 8% of the theoretical methanepotential. Consequently, lime pretreatment under the above recommended conditions canbe suggested for hydrolysis of chicken feathers to achieve significant enhancement of itsmethane potential.
48
Tynell, Åsa. "Microbial Growth on Pall-rings : A problem when upgrading biogas with the technique water absorption." Thesis, Linköping University, The Tema Institute, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-212.
Full textAbstract:
<p>Upgradering av biogas med tekniken vattenabsorption är vanligt i Sverige. Elva biogasanläggningar med tillsammans fjorton uppgraderingsanläggningar använder sig av tekniken. Problem med igensättning av fyllkroppar i absorptionskolonnen, samt i ett fall i desorptionskolonnen är vanligt förekommande och har en negativ effekt på uppgraderingen av rågas till fordonsgas. Fem av de nio anläggningarna i denna studie har problem med mikrobiell tillväxt på fyllkropparna. Syftet med denna rapport var att identifiera den mikrobiella tillväxten och avgöra vilka faktorer som reglerar den för att kunna rådge driftsansvariga hur man motverkar tillväxt.</p><p>En enkät skickades ut och studiebesök gjordes för att samla information om anläggningarna. Fosfolipidfettsyra (PLFA)-analyser utfördes för att bestämma mikrobiell biomassa och de organismer, som kan indikeras av de PLFA som är s.k. biomarkörer.</p><p>Prover samlades in från fyra uppgraderingsanläggningar: Jönköping, Kristianstad, Linköping och Uppsala. Proverna som samlades in var till utseendet olika, allt från gult slem från Linköping till röd-brun gegga som liknade kaffe-sump från Uppsala. I proverna från Linköping och Uppsala detekterades biomarkörer för metanoxiderande bakterier (metanotrofer) av typ I. Metanotrofer finns i jord, vatten och luft i miljöer med tillgång till metan och syre. I Jönköpingsproverna detekterades biomarkörer actinomyceter som är en vanligt förekommande bakterie i avloppsreningsverkens luftningsbassänger. Den mikrobiella tillväxten som samlades in från Kristianstad räckte enbart till ett prov och därför är det resultatet ej tillförlitligt.</p><p>I samtliga prover detekterades svamp (fungi) som förmodligen etablerats efter andra organismer.</p><p>Faktorer som kan anses påverka den mikrobiella tillväxten är processvattnets kvalitet, pH och temperatur. Rent vatten (dricksvatten) innehåller mindre mängd organiskt material, samtliga anläggningar som använder sig av avloppsvatten upplever problem. Lågt pH är gynnsamt för att minska den mikrobiella tillväxten eftersom de flesta organismer trivs bäst vid neutralt pH. Låg temperatur är gynnsam eftersom lösligheten för koldioxid och divätesulfid är större vid lägre temperaturer, vilket gynnar uppgraderingen av biogas.</p><br><p>Upgrading of biogas performed using the technique absorption with water wash is common in Sweden where eleven biogas plants, comprising a total of fourteen upgrading plants use this technique. However problems with microbial growth on the pall-rings in the absorption column, and in one case in the desorption column, have negative impact on upgrading the raw gas to vehicle gas. Five of the nine biogas plants studied here have experienced problems with microbial growth. The objective of this report was to identify the microbial growth and determine possible factors regulating microbial growth in order to give advice to process management.</p><p>A questionnaire was sent out and visits were made to the upgrading plants to collect information about the plants. A phospholipid fatty acid (PLFA) analysis was performed to determine microbial biomass and community structure, for which PLFA biomarkers are one type of indicator.</p><p>Samples were analysed from four upgrading plants: Jönköping, Kristinstad, Linköping and Uppsala. The cultures collected were visually different, varying from yellow and slimy to reddish brown with the consistency of coffee grounds. In the Linköping and Uppsala samples, biomarkers for methane-oxidising bacteria (type I methanotrophs) were detected. Methanotrophs live in environments with access to methane and oxygen and are inhibited by e.g. acetylene. In the Jönköping samples biomarkers indicating the bacteria actinomycetes common in the water of aeration tanks in sewage treatment plants, were detected. In Kristianstad there was only enough culture for one sample, so no reliable result was obtained. Fungi were detected in all samples and probably established after other organisms.</p><p>Factors affecting development of microbial growth were found to be water quality, pH and temperature of the process water. Clean water (drinking water) contains less organic material than cleaned water from sewage treatment plants. All plants using water from sewage treatment plants have experienced microbial growth. Low pH is beneficial for reducing microbial growth since most organisms prefer a neutral environment.</p><p>Low temperature is beneficial for minimising microbial growth since the solubility of carbon dioxide and hydrogen sulphide increases with decreasing temperature.</p>
49
Sund, Emil. "Självförsörjande hushåll med biogasproduktion och akvaponi." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229917.
Full textAbstract:
Energiförsörjningsteknologier behöver avanceras, oberoende av var i världen och i vilket syfte. Fossila bränslen bidrar till kraftiga växthusgasutsläpp när de förbränns och kretsloppet för dessa råvaror är en långsam process. Biogas är en av möjligheterna till utveckling då denna teknik i många fall kan använda råvaror mer tillgängliga för utvinning än de fossila, vilket möjliggör lokala energilösningar som kan bidra till att minska transporter, men framförallt mindre klimatpåverkande utsläpp. Detta då biogasens energikapacitet ligger i just mängden metan som gasen innehåller, vilket medför att teknologins utveckling strävar mot att ta tillvara på så mycket av denna växthusgas som möjligt, samtidigt som den stora biprodukten, koldioxid, är grön och ej bidrar till ökad växthuseffekt.Syftet med denna rapport är att bidra till utvecklingen av småskalig biogasproduktion, som idag ej är tillräckligt utvecklad för att kunna erbjuda självklara alternativ i situationer som har en god potential. Dessa situationer uppstår i exempelvis gårdsmiljöer där mycket avfall genereras i form av gödsel och jordbruksrester som är en utmärkt råvara för biogasproduktion. Men biogasanläggningar är idag optimerade för storskaliga verksamheter, som avloppsverk där stora volymer kommunalt avfall från hela städer hanteras. Mindre biogasanläggningar får problem med lönsamheten då volymerna idag är kraftigt kopplade till biogasavkastningen, men problem uppstår även vid drift och service av själva anläggningen då dessa är långt ifrån standardiserade och oftast platsbyggts för ändamålet.Biogas på ännu mindre skala, exempelvis i situationer med vanligt hushållsavfall har även det en potential då det i hushållen idag förbrukas väldigt mycket livsmedel, vatten och energi som med ett mer slutet kretslopp kan ta tillvara på mer resurser och på så sätt kan minska sitt ekologiska fotavtryck. Detta ledde till frågeställningen om hur det med en odling-och gårdsverksamhet kan, med hjälp av biogas, produceras en tillräcklig mängd mat och energi för att försörja ett hushåll.Arbetet inleddes med en litteraturstudie för att sammanställa data över viktiga parametrar och relevant bakgrundsinformation då mycket antaganden och schablonvärden behövde användas. Varje komponent i systemet fick input- och outputvärden gällande yta, energi, vatten m.fl. för att tillslut kunna uppskatta en landareal tillräcklig för matförsörjning, med eller utan energibalans.Resultaten från denna rapport visade att redan vid 593 m2 kunde ett hushålls matproduktion och förbrukning försörjas i ett år. Vidare utfördes en känslighetsanalys på viktiga variabler för att uppskatta hur ett framtida arbete med frågan bör utformas.<br>Around the world, energy supplying technologies need to advance regardless of its purpose of use. Burning of fossil fuels are the number one source of increase in greenhouse effect and its lifecycle is too long to be an option for the future. One of the more sustainable options is the production and use of biogas which utilizes more convenient resources like sewage waste, manure and domestic waste. This enables more local energy solutions and reduces the need for transport, but also contributes far less to the elevation and concentration of greenhouse gases in the atmosphere. The main component is methane which is also a potent greenhouse gas, but methane is also the one thing that is combustible in the gas and therefore the technology advances in utilizing more and more of this and reducing the loss fractions.Therefore, the purpose of this report is to contribute in the development of small-scale biogas production since most of the operating conditions today are optimized for large scale plants like sewage treatment plants, which handles much larger volumes of waste from whole towns and regions. The smaller scale operations are often in farm environments that have a lot of raw materials and wastes from their daily operations like manure and crop residues. Today these sizes struggle with profitability since biogas yield is strongly linked to production volume, and often maintenance becomes a problem because of on-site builds.The potential of biogas production is even located in smaller operations like household and domestic environments, mainly because of the high fraction of waste that originates in these sectors of society. Food waste and sewage are two important fractions that are being utilized today but mainly in scientific efforts or large-scale operations. This led to the question of how these two smaller-scale situations could work together, and how production of biogas could aid in becoming self-sufficient in food and energy consumption.The report started off with an overview of the literature on the subjects to help create a foundation for the many assumptions and template calculations that were required to model this situation. Each component in the system where given input- and output variables regarding energy, water and spacing required. This was then used to model a total area where it could take place.The results showed that already at 593 m2 you could grow enough food for a household to be self-sufficient for a year. This was without concern of energy usage which led to exceeding costs at about 540 000 SEK yearly, with a self-sufficiency rate of about 31 %. Furthermore, a sensitivity analysis was conducted on a few selected variables that was considered more uncertain which showed a variance in both total area and heating costs.
50
Dobrzanska, Dorota A. "Using bio-adhesive and bio-inert surfaces to maximize biogas production and influence microbial growth in anaerobic digesters." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/66487/.
Full textAbstract:
The optimisation of biogas digesters is crucial for further development of sustainable energy sources. In this research, an integrative approach was taken to understanding how this problem can be addressed including: seeking a better understanding of protein – surface interactions on the molecular level; larger scale experiments to screen the best materials for use in laboratory scale anaerobic digesters to influence microbial growth and biofilm development as well as analysis of farm-scale data using the ADM1 multiparameter model. The laboratory-scale experiments were undertaken to develop surfaces suitable for studying microbial immobilization. This work, currently using tertiary amines, amine oxides and comparator oligoethylene glycol studies the adsorption of two classic model proteins: lysozyme and fibrinogen using quartz crystal microbalance methods and represents important steps for selecting and exploring surface – protein interactions. The data showed that tertiary amine oxides are more resistant to nonspecific protein adsorption than the corresponding tertiary amines. Heat modified polyurethane foam was used to explore biofilm and planktonic phase microbial populations in a fixed film biogas reactor. After four weeks the foam was analysed by ‘next generation’ 454-sequencing to identify the influence of the supporting materials on microbial population residing in anaerobic digesters. The results revealed that Spirochaetes, Methanobacterium and Methanocorpusculum associated themselves with heat modified polyurethane foams. Finally, data from a farm-scale anaerobic digester (volatile fatty acid concentration, temperature and pH) have been gathered and entered into the ADM1 model, developed by the mathematical modelling group from Lund University, to mimic the behaviour of a laboratory scale 1.5 l reactor and identify improved conditions for methanogens stability. The combination of approaches described above will allow the identification of which parameters will enhance the operation of anaerobic digesters and has identified surfaces that promote adhesion of particular Bacteria and Archaea in order to increase biogas production.